Stretch Nylon:Continuous nylon filaments that are crimped and heat set to provide elasticity. Due to the relatively high level of elasticity imparted to nylon after it is crimped and heat set, it is very commonly utilized to make stretch socks in combination with other yarns.

X2O® Acrylic:An advanced moisture-absorbing acrylic fiber containing micropores that have a capillary capacity to absorb moisture, and then dissipate it by evaporation. It is one of the only moisture-absorbing acrylic fibers on the market. Although it is a lightweight fiber, it has superior insulation qualities and has antimicrobial properties as a result of the fact that the fiber contains chitosan, which is the natural material found in the shells of crabs and prawns. One of the remarkable characteristics of chitosan is its anti-bacterial and anti-mold characteristics.

Olefin:A superior, water-repelling fiber that won't accept moisture. It is used alone or with absorbent outer layers that work together to wick moisture away from your body. It is very strong and has the lowest specific gravity (lightest) of any man-made fiber. It is also stain-resistant and colorfast. The company that developed this fiber won the Nobel Prize.

Spandex:A man-made fiber with elastic properties that is often used in place of rubber. Used with other fibers, it provides elasticity, recovery, and close fit, primarily in the legs of socks to hold them in place and in the arch and ankle to provide extra support.